Reviving SLS on 123 wagon - PeachParts Mercedes-Benz Forum

jt20 · #1 03-12-2008, 08:34 PM

I am currently bringing a wagon back from the dead and someone yanked parts off my car during the repair process.
I have to reinstall the SLS reservoir and all the lines that are attached to it. - I have them on order.
I have searched and cannot find a similar posting to this since this system has been open for about a year now! What precautions should I take when refilling it... ie. flushing it perhaps before driving regularly? what about pressurizing and bleeding the system? Does the system bleed itself by pushing air into the reservoir and out the vent cap?
I have yet to even come in contact with this part of the system so I am working with little information.
Any suggestions are greatly appreciated.

tobybul · #2 03-12-2008, 10:03 PM

Is the oil pump still working?

Bio300TDTdriver · #3 03-12-2008, 10:15 PM

You can't pressurize the canisters. They are accumulators and they either still have pressure in them or they don't. Once the rubber fails the nitrogen is gone. If you are replacing parts of the system you probably need new accumulators as well.

jt20 · #4 03-12-2008, 11:32 PM

When the engine ran, fluid came out of the return line- red-ish, like auto tranny fluid. I can only assume so far that it does pump.

I was concerned about pressurizng the system (which it apparently does by itself) because of the way the FSM says to test the system. With pressure guage and and special attachments etc..
If I just continually fill the reservoir with fluid unil all the air is out of the system then the SLS should take of itself? This what I am asking about pressurization. And I mispoke about the 'canisters', I meant the reservoir.

I am not replacing parts because of failure.
They are MIA.

peterhardie · #5 03-13-2008, 07:59 AM

My fluid (MB) is clear, not red. Probably need to flush yours.

When you get the system sealed up, filling the cannister and running the engine should self-bleed the components. I have never pressure tested these, have owned three and worked on all three.

A bit of weight in the rear won't hurt. If you are putting new parts in, you should have no problem.

Mister Byrnzoil · #6 03-13-2008, 09:23 AM

there have been some excellent write-ups here about reviving a SLS system, I have read most of them, but I don't still understand how this system can be 'self bleeding', looking at the system if some air gets into the struts....how does it get out?

mobetta · #7 03-13-2008, 10:39 AM

it pushes it back into the valve, where it is returned to the res. The pump is always circulating oil to the valve and back. the valve opens and closes to allow more fluid to the struts, or less depending on load. if you start the car and jump up n down on the rear bumper, it will force most air out, and driving will get rid of the rest, in my experience...... and I have had the struts out and empty- that was all I did to bleed.

Chad300tdt · #8 03-13-2008, 11:00 AM

I took Mobetta's advice about the bleeding too. Jumping on the bumper to compress the struts while the engine was running pushed most of the air out. The rest of the air I missed bled out while driving. I tried using the bleeder on the valve and loading the rear with weight, but I only accomplished wasting fluid. The bleeder on the SLS valve is only to release the system pressure when you do repairs and can be used for fluid flushes. I prefer to do fluid flushes by catching the old fluid from the return line at the reservoir and fill with new FEBI until it comes out clean.

jt20 · #9 03-13-2008, 12:32 PM

That answers everything. Many thanks!
Although, have not been able to decode the acronym 'FEBI'. Is it at autozone or tractor supply?

Chad300tdt · #10 03-13-2008, 12:36 PM

FEBI is the brand of hydraulic fluid you should use. It's the same stuff as in the MB brand but cheaper.

http://catalog.peachparts.com/item.wws?clientid=catalog.peachparts&Sku=L7070-97881&mfr=AAA:FEB&sup=AAA&cookieID=29Y0IWSMD2BL0QYJZX&source=WWW.peachparts.COM&clientid=catalog.peachparts&source=WWW.peachparts.COM&clientid=catalog.peachparts

BTW, it's important to use the correct fluid due to the seals in the pump. I've read that there are conditioners in FEBI and MB fluid that help preserve the internal components of the pump. Cheaper fluid can be used for testing but the proper fluid needs to be used for actual road use.

peterhardie · #11 03-13-2008, 12:53 PM

You'll know if the pump seals go when you start seeing increased oil levels on your crankcase dipstick. The suspension fluid goes through the seals into the engine crankcase. Don't ask how much a pump costs.

jt20 · #12 03-13-2008, 02:17 PM

Quote:

Originally Posted by peterhardie

You'll know if the pump seals go when you start seeing increased oil levels on your crankcase dipstick. The suspension fluid goes through the seals into the engine crankcase. Don't ask how much a pump costs.

^^ Oh boy, can't can't wait for that to finally happen to me!

Where can I get FEBI? Is this an exclusive forum item.. or is it in stores?

Thanks for everyone's input, cleared everyhting up

Chad300tdt · #13 03-13-2008, 02:50 PM

I buy it online since I can't find it in the auto parts stores near me. You'll need 4 liters to do a complete flush. The system holds 3.5 liters. You can expect to pay at least $10 per liter anywhere.

Bajaman · #14 03-13-2008, 03:12 PM

Post #6 of this thread will tell you alternative oils to use http://www.***************/forum/showthread.php?t=494&page=1&pp=20
I bought the aero shell 4 at my local airport.

mobetta · #15 03-13-2008, 03:25 PM

I have found FEBI oil @ a local shop - metric auto parts. about $18/L when I was in a pinch. also napa here carries-"high end german hydraulic oil" of some sort- close to $30/L. I have found febi online for under $10, if you search.